package com.stylefeng.guns.core.intercept;

import com.stylefeng.guns.core.base.tips.ErrorTip;
import com.stylefeng.guns.core.common.constant.JwtConstants;
import com.stylefeng.guns.core.common.exception.BizExceptionEnum;
import com.stylefeng.guns.core.util.JwtTokenUtil;
import com.stylefeng.guns.core.util.RenderUtil;
import io.jsonwebtoken.JwtException;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Rest Api接口鉴权
 *
 * @author stylefeng @Date 2018/7/20 23:11
 */
public class RestApiInteceptor extends HandlerInterceptorAdapter {

  @Override
  public boolean preHandle(
      HttpServletRequest request, HttpServletResponse response, Object handler) {
    if (handler instanceof org.springframework.web.servlet.resource.ResourceHttpRequestHandler) {
      return true;
    }
    HandlerMethod handlerMethod = (HandlerMethod) handler;
    return check(request, response, handlerMethod);
  }

  private boolean check(
      HttpServletRequest request, HttpServletResponse response, HandlerMethod handlerMethod) {
    if (request.getServletPath().equals(JwtConstants.AUTH_PATH)) {
      return true;
    }
    final String requestHeader = request.getHeader(JwtConstants.AUTH_HEADER);
    String authToken;
    if (requestHeader != null && requestHeader.startsWith("Bearer ")) {
      authToken = requestHeader.substring(7);

      // 验证token是否过期,包含了验证jwt是否正确
      try {
        boolean flag = JwtTokenUtil.isTokenExpired(authToken);
        if (flag) {
          RenderUtil.renderJson(response,new ErrorTip(BizExceptionEnum.TOKEN_EXPIRED.getCode(),BizExceptionEnum.TOKEN_EXPIRED.getMessage()));
          return false;
        }
      } catch (JwtException e) {
        // 有异常就是token解析失败
        RenderUtil.renderJson(
            response,
            new ErrorTip(BizExceptionEnum.TOKEN_ERROR.getCode(), BizExceptionEnum.TOKEN_ERROR.getMessage()));
        return false;
      }
    } else {
      // header没有带Bearer字段
      RenderUtil.renderJson(
          response,
          new ErrorTip(BizExceptionEnum.TOKEN_ERROR.getCode(), BizExceptionEnum.TOKEN_ERROR.getMessage()));
      return false;
    }
    return true;
  }
}
